The total agreement is valued at $804.0 million with the U.S. Air Force investing two-thirds of the funding required to complete development of the AR1 engine by the end of 2019, Aerojet Rocketdyne reports.

The total potential U.S. government investment, including all options, is $536.0 million, the company reports. The total potential investment by Aerojet Rocketdyne and its partners, including all options, is $268.0 million. Under the terms of the AR1 agreement, the Air Force contributions are recognized proportionately as an offset to R&D expenses.

The Air Force thus far has funded about $135.3 million of the R&D costs and ULA has funded about $9.2 million, with net Aerojet Rocketdyne applied contract costs reaching about $51.8 million, the company reports. There additional costs, such as those expensed, but not yet expensed or applied to contracts.

SpaceX has publicly indicated that the development cost for Falcon 9 launch vehicle was approximately $300 million. Additionally, approximately $90 million was spent developing the Falcon 1 launch vehicle which did contribute to some extent to the Falcon 9, for a total of $390 million. NASA has verified these costs.